1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to a refrigerator which has a device for preventing flow of air between an evaporator and a cooling compartment during a defrosting operation and when a door is open.
2. Related Art
In general, as shown in FIG. 1, a refrigerator has a compressor 14 for compressing refrigerant, an evaporator 7 for generating cool air by evaporating the refrigerant supplied from the compressor 14, and a fan 10 for blowing the cool air generated by the evaporator 7. A duct member 12 for forming a cool air duct is installed at the rear part of a fresh food compartment 3. The duct member 12 has a plurality of cool air discharge ports 13 opened in the fresh food compartment 3. The cool air blown by the fan 10 flows into the cool air duct, and then is supplied into the fresh food compartment 3 through the cool air discharge ports 13.
The fresh food compartment 3 is opened and closed by a door 2, and the fresh food compartment 3 is partitioned into a plurality of spaces by shelves 4. At the upper part of the fresh food compartment 3, a cover 5 for shielding the evaporator 7 is installed. The evaporator 7 is fixed by a holder 8 in a space 6 formed by the cover 5.
While the refrigerator operates, frost is generated on the evaporator 7. The cooling efficiency of the evaporator 7 is lowered by the frost. Hence, the refrigerator is equipped with a heater 9 for removing the frost, and performs defrosting operation by heating the evaporator 7 using the heater 9 when the refrigerator is used more than a predetermined period of time.
In such a conventional refrigerator, there is a problem that the heat generated by the heater 9 during the defrosting operation is transmitted into the fresh food compartment 3. The heat generated by the heater 9 is mainly transmitted through the same path with the path for supplying the cool air. That is, the heat is mainly transmitted to the fresh food compartment 3 through the cool air duct and the cool air discharge ports 13. Due to the heat transmitted to the fresh food compartment 3, the cooling efficiency of the fresh food compartment 3 is lowered, and the status of the food stored therein cannot be maintained properly.
Furthermore, there is a problem that the cool air generated by the evaporator 7 is continuously supplied into the fresh food compartment 3 even when the door 2 is open, so the supplied cool air flows outside, which is a loss of the cool air. Furthermore, outside warm air flows toward the evaporator 7 of which surroundings lie in a lower pressure than the other areas, whereby more frost is generated on the evaporator 7. Therefore, the defrosting operation must be performed more frequently. In order to perform the defrosting operation, the heater 9 should radiate heat, so the cooling efficiency is still more lowered by the frequent defrosting operation.